Instruction Manual

748467-A January 2002

Model MicroCEM

2-5 ANALYTICAL LEAK CHECK

a. Flow Indicator Method

If explosive or hazardous gas samples are being measured with the MicroCEM, it is recommended that gas line fittings and components be thoroughly leak-checked prior to initial application of electrical power, bimonthly intervals thereafter, and after any maintenance which involves breaking the integrity of the sample containment system.

Supply air or inert gas such as nitrogen, at 10 psig (689 hPa), to the analyzer through a flow indicator with a range of 0 to 250 cc/min. Install a shut-off valve at the sample gas outlet. Set the flow rate to 125 cc/min.

Close the outlet shut-off valve and notice that the flow reading drops to zero. If the flow reading does not drop to zero, the system is leaking and must be corrected before the introduction of any flammable sample gas or application of power.

MicroCEM Analyzer

Inlet

Outlet

N2

Flow Meter

10psig

(69 kPa)

Gas Outlet

Figure 2-7. Leak Test Flow Method

2-14

Installation

Rosemount Analytical Inc. A Division of Emerson Process Management